Actually the last Firefox UI was Chrome. Or at least I stopped being able to tell the difference.
I am hearing this comment a lot but I am not seeing it. First I thought on my Debian install, the nice people at GNU had changed the code in Icecat 5 to preserve the old look and feel, but my Firefox on Windows looks exactly the same.
I still have a menu bar, I still have the navigation buttons to which I can add and remove buttons. Just go to Firefox|Options and select what toolbars you want.
The other changes such as the status bar and the tab positions are not a big deal either. Link details still appear at the bottoms of the screen. Tabd above the address bar, after some thought make a lot of sense, because that address belongs to that tab.
Firefox is not actually as bad as you might think. In my case I moved to Firefox because the webkit based browsers on my Debian install had poor performance and rendering issues (although I liked Arora very much).